export default {
  namespaced: true,
  state: () => ({
    // 购物车的数组，用来存储购物车中每个商品的信息对象
    // 每个商品的信息对象，都包含如下 6 个属性：
    // { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
    cart: JSON.parse(uni.getStorageSync('cart') || '[]')
  }),

  mutations: {
    addToCart(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if (!findResult) {
        state.cart.push(goods)
      } else {
        findResult.goods_count++
      }
      this.commit('m_cart/saveToStorage')
    },
    saveToStorage(state) {
      uni.setStorageSync('cart', JSON.stringify(state.cart))
    },
    updateGoodsState(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if (findResult) {
        findResult.goods_state = goods.goods_state
        this.commit('m_cart/saveToStorage')
      }
    },
    updateGoodsNum(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if (findResult) {
        findResult.goods_count = goods.goods_count
        this.commit('m_cart/saveToStorage')
      }
    },
    removeGoodsById(state, goods) {
      state.cart = state.cart.filter(x => x.goods_id !== goods.goods_id)
      this.commit('m_cart/saveToStorage')
    },
    updateAllGoods(state, newState) {
      state.cart.forEach(x => x.goods_state = newState)
      this.commit('m_cart/saveToStorage')
    }
  },
  getters: {
    total(state) {
      // let c = 0
      // state.cart.forEach(x => c += x.goods_count)
      // return c
      return state.cart.reduce((c, state) => {
        return c += state.goods_count
      }, 0)
    },
    checkedCount(state) {
      return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count, 0)
    },
    checkedGoodsAmount(state) {
      return state.cart
        .filter(x => x.goods_state)
        .reduce((total, item) => {
          return total += item.goods_count * item.goods_price
        }, 0)
        .toFixed(2)
    }
  }
}